Is there a standard option workflow in F#?

Question

Is there an option (maybe) wokflow (monad) in the standrd F# library?

I\'ve found a dozen of hand-made implementations (1, 2) of this workflow, but I don\'t really w

Answer 1

I've create an opensource library FSharp.Interop.NullOptAble available on nuget.

It not only works as an option workflow, but it works as a null or nullable workflow as well.

let x = Nullable(3)
let y = Nullable(3)
option {
    let! x' = x
    let! y' = y
    return (x' + y')
} (* |> should equal (Some 6) *)

Works just as well as

let x = Some(3)
let y = Some(3)
option {
    let! x' = x
    let! y' = y
    return (x' + y')
} (* |> should equal (Some 6) *)

Or even

let x = "Hello "
let y = "World"
option {
    let! x' = x
    let! y' = y
    return (x' + y')
} (* |> should equal (Some "Hello World") *)

And if something is null or None

let x = "Hello "
let y:string = null
option {
    let! x' = x
    let! y' = y
    return (x' + y')
} (* |> should equal None *)

Finally if you have a lot of nullable type things, I have a cexpr for chooseSeq {} and if you yield! something null/None it just doesn't get yielded.

See more examples here.